bluetooth controller not working after sending few messages - bluetooth

Question

I have a simple bluetooth code to activate a relay.
it is from an old project and it used to work fine, but I was sending just bit in the past, this time I have to send strings.
With this code I can send six command and then the device doesn't respond anymore. when I stop the application suddenly all the commands "un-executed" before are executed by the relay board. If I change the size of the buffer it seems to have some effect on the number of messages I can send.
I am using an old phone a controller with Android 2 and API 10
Any idea where I should investigate?
Thanks
public class Menuuu extends Activity {
BluetoothAdapter mBluetoothAdapter;
BluetoothSocket mmSocket;
BluetoothDevice mmDevice;
OutputStream mmOutputStream;
InputStream mmInputStream;
String a;
Editable b;
final byte[] buffer = new byte[2048];
private ToggleButton T1;
private static final String TAG = "MyActivity";
public void write_buf(byte[] buffer) {
try {
mmOutputStream.write(buffer, 0, 1024 );
mmOutputStream.flush();
} catch (IOException e) { }
}
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final ToggleButton T1 = (ToggleButton) findViewById(R.id.Button1);
T1.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (T1.isChecked()) {
// TODO Auto-generated method stub
buffer[0] = 'r';
buffer[1] = 'e';
buffer[2] = 'l';
buffer[3] = 'a';
buffer[4] = 'y';
buffer[5] = ' ';
buffer[6] = 'o';
buffer[7] = 'n';
buffer[8] = ' ';
buffer[9] = '0';
buffer[10] = ' ';
buffer[11] = '\r';
buffer[12] = '\n';
}
if (!T1.isChecked()) {
// TODO Auto-generated method stub
buffer[0] = 'r';
buffer[1] = 'e';
buffer[2] = 'l';
buffer[3] = 'a';
buffer[4] = 'y';
buffer[5] = ' ';
buffer[6] = 'o';
buffer[7] = 'f';
buffer[8] = 'f';
buffer[9] = ' ';
buffer[10] = '0';
buffer[11] = '\r';
buffer[12] = '\n';
}
write_buf(buffer);
}
});
void findBT() throws IOException
{
mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
if(!mBluetoothAdapter.isEnabled())
{
Intent enableBluetooth = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBluetooth, 1);
}
Set<BluetoothDevice> pairedDevices = mBluetoothAdapter.getBondedDevices();
if(pairedDevices.size() > 0)
{
for(BluetoothDevice device : pairedDevices)
{
if(device.getName().equals(a))
{
mmDevice = device;
break;
}
}
}
UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805f9b34fb"); //Standard //SerialPortService ID
mmSocket = mmDevice.createRfcommSocketToServiceRecord(uuid);
mmSocket.connect();
mmOutputStream = mmSocket.getOutputStream();
mmInputStream = mmSocket.getInputStream();
public boolean onCreateOptionsMenu(Menu menu){
super.onCreateOptionsMenu(menu);
MenuInflater h= getMenuInflater();
h.inflate(R.menu.hardmenu,menu);
return true;
}